The autumn of 1789 and the whole of the year 1790 were passed in the debate and promulgation of rapid and drastic reforms, by which the Parliament within eighteen months reduced the monarchy to little more than a form.  Mirabeau, the most popular member, and in a sense the leader of the Parliament, secretly agreed with the court to save the monarchy from destruction; but on his sudden death, on April 2, 1791, the king and queen, in terror at their situation, determined to fly from Paris.  The plan, which was matured during May and June, was to reach the frontier fortress of Montmedy by way of Chalons, and to take refuge with the army on the frontier.

The royal family made every preparation for departure; very few persons were informed of it, and no measures betrayed it.  Louis XVI. and the queen, on the contrary, pursued a line of conduct calculated to silence suspicion, and on the night of June 20 they issued at the appointed hour from the chateau, one by one, in disguise, and took the road to Chalons and Montmedy.

The success of the first day’s journey, the increasing distance from Paris, rendered the king less reserved and more confident.  He had the imprudence to show himself, was recognised, and arrested at Varennes on the 21st.

The king was provisionally suspended—­a guard set over him, as over the queen—­and commissioners were appointed to question him.

IV.—­Europe Declares War on the Revolution

While this was passing in the Assembly and in Paris, the emigrants, whom the flight of Louis XVI. had elated with hope, were thrown into consternation at his arrest.  Monsieur, who had fled at the same time as his brother, and with better fortune, arrived alone at Brussels with the powers and title of regent.  The emigrants thenceforth relied only on the assistance of Europe; the officers quitted their colours; 290 members of the Assembly protested against its decrees; in order to legitimatise invasion, Bouille wrote a threatening letter, in the inconceivable hope of intimidating the Assembly, and at the same time to take up himself the sole responsibility of the flight of Louis XVI.; finally the emperor, the King of Prussia, and the Count d’Artois met at Pilnitz, where they made the famous declaration of August 27, 1791, preparatory to the invasion of France.

On April 20, 1792, Louis XVI. went to the Assembly, attended by all his ministers.  In that sitting war was almost unanimously decided upon.  Thus was undertaken against the chief of confederate powers that war which was protracted throughout a quarter of a century, which victoriously established the revolution, and which changed the whole face of Europe.

On July 28, when the allied army of the invaders began to move from Coblentz, the Duke of Brunswick, its commander-in-chief, published a manifesto in the name of the emperor and the King of Prussia.  He declared that the allied sovereigns were advancing to put an end to anarchy in France, to arrest the attacks made on the altar and the throne.  He said that the inhabitants of towns who dared to stand on the defensive should instantly be punished as rebels, with the rigour of war, and their houses demolished or burned; and that if the Tuileries were attacked or insulted, the princes would deliver Paris over to military execution and total subversion.